package MyDoc;

public class Test {
    public static void main(String[] args) {
        String path="E:/蒋金鑫/传过来的文件/过年了.";
       /* StringBuilder sb = new StringBuilder(path);
        sb.append(path);
        sb.append("MP4");
        //String str =sb.toString();
        System.out.println(path);*/
       int index=path.lastIndexOf(".");
        System.out.println(index);
    }
}
